Method of separating borneol from pine oil



June 27,` 1933. L T sMlTH v METHOD oF SEPARATING BORNEOL FROM PINE OIL Filed Aug. 11, 1927 UPM " "'UNITED? STATS' Patented June 277, 1933 n 1 LEE'T. SMITH, oi? KENVIL; Nnwaansn, AssieNon 'roanne-Unas Pownnn. coiv'rPANY,

- or WILMINGTON, DELAWARE, AcoanoaA'rro-N oa DELAWARE therefrom Y,ofthe yborneol.` Ivlierecovery of r` AMETHon-on SEPARATING BBNEOL FROM PINE 'CIL Application led August 11, 1927.- Serial No. 212,300.

My inventionv relates toa method forthe separation of borneol from pine oil. f Heret'ofore `borneol having .a Aboiling point of about 212 C. and a melting point of. about V206" C. has ,been recognized as a constituent of pine oil. f

, Borneol, which finds found in nature and has been separated from pine oil, butheretofore only,v by methods involvingV the chemicalrtreatinent of they pine oil, distillation of the treated pine oil and treatment of theresiduel for ythe separation borneol from theresidue of chemically treated pine oil vis relatively expensive and the yield of borneol is relatively small.

't' is. ,the,objectof my invention to NOW provideV method whereby borneol may be separatedfrom pine oilwithout the necessity `for whereby a relatively large yield may be ob-- chemical treatment of the pine `oil, and

tained `at a minimum of expense.

n According to 4my invention Ihave discovered that borneolfis highly soluble'in "terpineol, especially alpha-,terpineoh a constituent ofvpine `oiland that this solubility y intheterpineol, prevents the effective separa- ,tion vof theborneol from the pine oil byv methods heretofore* practiced, such as by fraction- 'ationlf According to my invention from` the t broad standpoint, I fractionate pine oil to btain'a fraction grelativelyrich in borneol Y and then separatefrom the fraction the al- 'Kpha-ter'pineol in which the fraction isy sublstantially rich and in which, as has been inrdicated,the borneol is soluble, since'. the boiling points of terpineol andborneolare rela- 1 tivelyclose;` :24o

' After separation-of the alphaterpineohwhich may be caused toy crystallize and may ,then be separatedout, I have discovered that the. borneol may be, separated from the fraction in solidformandkrelatively purewith little difficulty. n y

According to the method embodying my invention,for-example, pine oil, such yasis derived from :pine'wood-by any 'wellknown method, is Ifractionated and' a cut -or fractionfboiling `Within the range from about 2,05%@-220o ,Gf Separated. Preferably' a its `principal use in VVconnection-withthe making of camphor, isY

fraction boiling within the narrower range from about 214 C. to aboutf2l6 C. is separated and the alpha-terpin'eol, a constituent of the pineoil and contained in the cut, separated out. The alpha-terpineol may be separated out, for example, by re'frigerating the cut, or seeding the cut with a crystal ofzalphaterpineol to effect crystallization of the y be separated by filtration or centrifugation,

the mother liquor is refractionated to obtain cuts rich in-borneol which are cooled to -effect precipitation of borneol. Borneol freezes at' about 206 C., but it is preferable that the cuts rich in borneol obtained from the refrac- .tionation of the mother liquor be cooled -to substantially below 00y C.' in order to facilitate solidifying of the borneol. The cuts rich in borneol obtained'from the refractionation of the mother liquor, after they have been cooled, may be kseeded to facilitate solidiflcation of the borneol or solidification of the borneol may be induced by mechanical means. The solidified bornecl is separated from its mother liquor by filtration or centrifugation.

. As a further example of the carrying out of the method embodying my invention and with reference to the accompanying drawing in which is shown a flow sheet, the pine oil may be initially fractionated into, for example, cuts numbered"`l-r on the accompanying drawing. Cuts #l and qll-T are set aside while'cut #6 is treated for thecrystallization vtherefrom' of alpha-terpineol, which' may be effected, for example, by refrigeration, seeding, or mechanical means and the crystallized alpha-.terpineol is separated by filtrationor n centrifugation. The mother liquor from cut 'Cut #2 is refra-tionated into cuts numbered 8, 9 and l()l on the accompanying drawing. ACut #8 is set aside, while cut .#10 is added to drawing. 'out #11 is #ideate cui #9, while #17 is added'to cut #15,1 'ls'treated as by refrigeration, seedmg or mecut #13 is added to cut #4, Which is then refractionated to cuts numbered 14, 15 and 16 on the accompanying drawing. Cut .#141 is added `to cut V#12', While cut #16 is added to' the combinationfcf cutv#5 and the mother liquorof cut #6 obtained after the removal y' of rvcrystallized Y alpha-terpineol therefrom.

Cut'#5to which, asis clear, has been added cut #16 and the motherliquorofcut #6, is

then refractionated into cuts numbered 17, 18 and 19 on the accompanying drawing. Cut ile cut #19 1s chanical means to effect crystallization of alpha-terpineol therefrom, which issepa- Vrated from the-mother liquor byliltration or terpineol has beens'e'parated by lirst eiecting"v centrifugationgandfthe mother Vliquor added v 't0-cur.' #18; Cut-,s #9, #12,`

Y #.15 and #18 are respectively refractionated'l y `Borneol isseparated from the'several 'cuts'.

and 'from the 'cuts 'from which :the .alphacrystallization of the bcrneol as? by refrigeraf tion, seeding .orA mechanical 'means and then -effectingits separation by filtration or' cenvtrifugation'.A l

terpineol'ffrom theconcentrated cuts which,

i as will be understod, is concentrated 'with the bOrneol and 'in which lthe borneol is so soluble "as toprevent its recovery until after the' removal of thealph'a-terpineol, which Ihave discovered may be readily removed enabling my invention the pine oil is fractionated toV Vobtain-,a kconcentration Vof lborneol, and thesubsequentready recovery of the borneoll by electing its crystallization.'

. It will now. be yobserved thaty by virtue of my invention a method of substantial simplicl f ity and economy is provided for the separation of borneolffrom pine oil and by the pracy. tice of which borneolis recovered inl desirable form 'and in a state of substantial purity.' if

f In connection with the separationfof borneol, it should `be noted Vthat accordingto alpha-terpineol ywhich is to a'substantialextent also concentrate'dandv in' which the b orjneol is soluble is then eliminated by crystallization, thus releasing the borneolv from solution 'in thelalpha-terpineol and 'renderiingits releasefromvsolution infthe mother liquor comparativelysimple. The practicae bility yof the process 'ac cording'ton'iy inf vention depends" upon the discovery lthat while the borne/ol is highly vsoll'lblevin alphaterpineol, it is sufficiently ksoluble 'in the mother lliquor so that itvivill not crystallizev yproducts out with the alpha-terpineol and that when the alpha-terpineol is removed from the mother liquor, as by crystallization, the borneolwill readily separate after further fractionation fromA the mother liquor bycooling sufficiently to cause itto freeze orr solidify, though lit will be understood-that ncrystallization Vof the borneoljmaybe effected after cooling the mother liquor by seeding, or induced by mechanical means. y

It will be understood that the fractiona- Lftion and refractionation of the pine oil and yof theseveral cuts may be carried out with 0r Without steami'and ,under ordinary atmospheric pressure or under reduced pressure. Eli'ecting the fractionations under reduced pressure is desirable, since lower tempera.- ture may be used with leesgdecomp'osition and polymerization and-with the recovery of EossessingA a #more pleasant odor a ly more nearly pure.

and' prob i 'l It will be understod theta@ carrying out of my inventionas 'described herein specilifcally with reference' to the; accompanying of example only and shall f drawing is by 'We not betaken asfr'llmitingmy inventi'nfin its Having no'W fully described invention, what I'claim and desire to protect hy'Letters 1. The method of separating borneol from pine Voil, which .includes fractionatin the pine `oil to obtaina `cuty rich in'borneo `and terpineol and which will boil at normalatmospheric pressure' largely within the''i-ange about 205 C.-'-220 crystallizing'terpineol present inthe cut separating the crystallized terpineol from' the mother lliquor fractionating thermother liquor toobtain cuts richl in l 2.' The method of'separatingborneblfrom pine poil,nwhicl1, includes fractionating-ithe pine o'il to obtain 4a cut boiling yat normal atmospheric )pressure largely L Withinl 'the rangexabout 214"4v C.21'6C.`, eectiny crystallization of alpha-terpineol 'from t le cut, f separating the crystallized .alpha-terpineol from they motherliquor fractio'nating;the"V mother liquor tdobtai'n cuts richyinborneol and eifecting the crystallizationv of" bornel from cuts rich inborneol obtained 4from the a yThemailed: #separating temeer vfrom' pine oil, which includes fractionating the pineV oil to obtain a'cut boiling within the l Vrange about 20591C-220j C., velfec'ting"crystallization of terpineol fromthecut, filtering *out* the crystallized terpineol, refrac- "tionating the filtrate 'to obtainV of cuts, eifecting the crystallization of 'bor-y -neol from cuts of' 'the filtrate which arerich a plurality in borneol, y separating v out] the crystallized jborneol and fractionating the mother liquorV borneol and effecting crystallization-f horsneol from cuts rich in borneol obtained 'from to obtain cuts relatively rich in borneol and eiecting crystallization of additional borneol `from cuts relatively rich in borneol obtained from thefmother liquor.

In testimony of which invention, I have hereuntovset Inyhand, at Kenvil, New Jersey, on-this 1st day of August, 1927. e

LEE T. SMITH.

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